Actinogen Launches Extension Giving Trial Patients 25 Months of Treatment
Actinogen launches open-label extension of XanaMIA Alzheimer’s trial
Actinogen Medical (ASX: ACW) has commenced the open-label extension (OLE) phase of the XanaMIA trial with the first participant treated on 31 March 2026. The OLE phase means all XanaMIA participants now have access to active Xanamem therapy for up to 25 months, generating additional long-term safety and efficacy data to support future regulatory submissions.
The OLE runs in parallel with the ongoing randomised phase of the trial, which remains on track to deliver topline results in November 2026. While the randomised phase compares Xanamem against placebo in 247 patients with mild to moderate Alzheimer’s disease, the OLE allows all former and current participants to receive active treatment at 10 mg once daily across trial sites in Australia and the United States.
Key highlights of the OLE phase:
- All participants receive active Xanamem 10 mg once daily with no placebo control group
- Treatment duration of up to 25 months
- Open to all former and current participants who have completed the randomised phase
- Generates longer-term safety data and observational efficacy data on CDR-SB, cognition, and activities of daily living
- Data can be analysed and reported progressively, with comparison to historical control cohorts of patients with mild to moderate Alzheimer’s disease
- Provides a valuable contribution to future regulatory marketing applications
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What is an open-label extension and why does it matter?
An open-label extension trial is a clinical study phase where all participants receive the active treatment rather than placebo. Both patients and researchers know what therapy is being administered, allowing for the collection of longer-term safety and efficacy data beyond the controlled randomised phase.
OLE phases serve a specific regulatory purpose by demonstrating the durability of a therapy’s benefit over extended treatment periods. This data strengthens marketing applications by showing that the treatment effect is maintained, not just a short-term phenomenon. For investors, OLE data provides additional evidence that can support partnership discussions and regulatory submissions.
The XanaMIA-OLE will evaluate safety alongside key efficacy endpoints, with results analysed progressively throughout the 25-month treatment period. Because OLE data can be compared against historical control cohorts of patients with mild to moderate Alzheimer’s disease, it may provide additional context for Xanamem’s potential benefit ahead of the November 2026 topline readout from the randomised phase.
Key efficacy endpoints under evaluation
The OLE phase tracks three primary categories of clinical outcomes:
- CDR-SB (Clinical Dementia Rating Scale – Sum of Boxes): The internationally recognised primary endpoint for Alzheimer’s trials, measuring functional and cognitive decline across six domains
- Cognition: Assessments of memory, reasoning, awareness, and decision-making capabilities
- Activities of daily living: Evaluation of patients’ ability to perform routine tasks independently
Xanamem’s differentiated safety profile
Dr Dana Hilt, Actinogen’s Chief Medical Officer, said the OLE represents an important opportunity for trial participants, half of whom initially received placebo.
Dr Dana Hilt, Chief Medical Officer
“The commencement of the open-label extension phase of the XanaMIA trial means that we can now offer current and past participants the opportunity to receive active Xanamem therapy for up to 25 months. This is an important opportunity for our trial participants, half of whom initially received placebo, as it enables all participants to contribute valuable data on the potential durability of Xanamem benefit and long-term safety.”
Dr Hilt also highlighted Xanamem’s potential differentiation from current antibody-based Alzheimer’s therapies.
Dr Dana Hilt, Chief Medical Officer
“Xanamem has the potential to be a game-changer for Alzheimer’s patients as a potentially safe and effective oral therapy to slow or halt disease progression. Unlike anti-amyloid antibody therapy, Xanamem does not require serial MRI scanning for safety evaluations as there is no suggestion it causes brain swelling also known as ‘ARIA’.”
ARIA (Amyloid-Related Imaging Abnormalities) refers to brain swelling or bleeding observed with anti-amyloid antibody therapies, requiring regular MRI monitoring for patient safety. The absence of ARIA risk positions Xanamem as a potentially more accessible treatment option, eliminating the need for frequent imaging appointments. Combined with once-daily oral administration, this profile offers convenience advantages in a market where current alternatives require infusions and intensive safety monitoring.
Trial design at a glance
The XanaMIA Phase 2b/3 trial enrolled 247 patients with mild to moderate Alzheimer’s disease and progressive disease, confirmed by elevated pTau181 protein biomarker levels in blood. Patients receive Xanamem 10 mg or placebo once daily over a 36-week treatment period.
| Parameter | Detail |
|---|---|
| Phase | 2b/3 |
| Patients enrolled | 247 |
| Treatment duration | 36 weeks |
| Primary endpoint | CDR-SB |
| Topline results | November 2026 |
The trial has passed an independent Data Monitoring Committee safety and efficacy futility review, supporting its continuation to final readout. The randomised phase remains closed to new participant recruitment and continues in parallel with the OLE.
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What investors should watch for next
The commencement of the OLE creates a dual-track clinical programme. The randomised phase progresses toward November 2026 topline results, whilst the OLE generates ongoing safety and observational efficacy data over up to 25 months of treatment.
Because OLE data can be analysed progressively, investors may receive interim updates before the pivotal November 2026 readout. This progressive analysis allows comparison against historical control cohorts, potentially providing additional evidence of Xanamem’s benefit profile.
The OLE data will contribute directly to future regulatory marketing applications, strengthening the overall evidence package submitted to authorities. Positive long-term safety and durability data could support partnership discussions and commercial positioning.
Xanamem’s oral delivery and differentiated safety profile address key limitations of current Alzheimer’s therapies. The absence of ARIA risk removes the need for serial MRI scanning, potentially reducing treatment costs and improving patient accessibility compared to antibody-based alternatives requiring infusion and intensive monitoring. As the Alzheimer’s treatment landscape evolves, therapies offering both efficacy and practical advantages in administration and safety monitoring may attract significant commercial interest.
The November 2026 topline results from the randomised phase remain the critical near-term catalyst, whilst the OLE provides additional validation of Xanamem’s long-term profile.
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